Downhole tools containing ductile cementing materials

ABSTRACT

A downhole tool for controlling the flow of a fluid in a wellbore includes a component that comprises: a cementitious material; an aggregate; and a ductility modifying agent comprising one or more of the following: an ionomer; a functionalized filler; the functionalized filler comprising one or more of the following: functionalized carbon; functionalized clay; functionalized silica; functionalized alumina; functionalized zirconia; functionalized titanium dioxide; functionalized silsesquioxane; functionalized halloysite; or functionalized boron nitride; a metallic fiber; or a polymeric fiber.

BACKGROUND

Frac plugs are commonly used downhole tools. Frac plugs can isolatezones in a well, allowing pressurized fluids to treat the target zone orisolated portion of a formation. In operation, forces apply tocomponents of a frac plug and urge a seal member to deform and fill aspace between the plug and a casing. The setting load can be as high as60,000 lbf. Upon setting, the plug can also be subjected to high orextreme pressure conditions. Accordingly, plugs includes variouscomponents thereof must be capable of withstanding high pressures orforces during the setting and subsequent fracturing operations. Toincrease the compressive strength of plug components, filament windingor filler orientation techniques have been used. However, the cost maybe less than desirable due to machining procedures and the materialsused. There is a continuing need in the art for tools or components oftools that have high compressive strength and are cost effective. Itwould be a further advantage if such tools or components can be readilymade.

BRIEF DESCRIPTION

A component for a downhole tool comprises: a cementitious material; anaggregate; and a ductility modifying agent comprising one or more of thefollowing: an ionomer; a functionalized filler; the functionalizedfiller comprising one or more of the following: functionalized carbon;functionalized clay; functionalized silica; functionalized alumina;functionalized zirconia; functionalized titanium dioxide; functionalizedsilsesquioxane; functionalized halloysite; or functionalized boronnitride; a metallic fiber; or a polymeric fiber.

Also disclosed is a downhole tool comprising the component. In anembodiment, A downhole tool for controlling the flow of a fluid in awellbore comprises an annular body having a flow passage therethrough; afrustoconical member disposed about the annular body; a seal membercarried on the annular body and configured to engage a portion of thefrustoconical member; and a bottom sub disposed about the annular body;wherein at least one of the frustoconical member and the bottom subcomprise: a cementitious material; an aggregate; and a ductilitymodifying agent comprising one or more of the following: an ionomer; afunctionalized filler; the functionalized filler comprising one or moreof the following: functionalized carbon; functionalized clay;functionalized silica; functionalized alumina; functionalized zirconia;functionalized titanium dioxide; functionalized silsesquioxane;functionalized halloysite; or functionalized boron nitride; a metallicfiber; or a polymeric fiber.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description should not be considered limiting in any way.With reference to the accompanying drawings, like elements are numberedalike:

FIG. 1 illustrates the crosslinking between ionomers in a cementingcomposition according to an embodiment of the disclosure;

FIG. 2 illustrates the crosslinking between functionalized carbon in acementing composition according to an embodiment of the disclosure;

FIG. 3 illustrates the crosslinking between an ionomer andfunctionalized carbon in an exemplary cementing composition; and

FIG. 4 illustrates an exemplary embodiment of a downhole tool that iseffective to control fluid flow.

DETAILED DESCRIPTION

The inventors have discovered that components having improved strengthand ductility at the same time can be made from cementing compositionscomprising a ductility modifying agent such as an ionomer;functionalized filler; a metallic fiber; a polymeric fiber; or acombination thereof. In addition to the ductility modifying agent, thecementing composition can also contain a cementitious material and anaggregate. Advantageously, the components can be used in tools such asfrac plugs and bridge plugs to control fluid flow. More than onecomponent can include the cementing compositions.

As used herein, ionomers are polymers that comprise ionic groups bondedto a neutral polymer backbone. The ionomers can be a homopolymer or acopolymer derived from two or more different monomers. Suitable ionicgroups include a sulfonate group, a phosphonate group, a carboxylategroup, a carboxyl group, a sulfonic acid group, or a phosphonic acidgroup. Combinations of the ionic groups can be used. The ionomers canhave an ionic group content of about 0.5 mol % to about 20 mol % orabout 3 mol % to about 10 mole % based on the total weight of theionomers.

Ionomers can be prepared by introducing acid groups to a polymerbackbone. If needed, the acid groups can be at least partiallyneutralized by a metal cation such as sodium, potassium, calcium, orzinc. In some embodiments, the groups introduced are already neutralizedby a metal cation. The introduction of acid groups can be accomplishedin at least two ways. In a first method, a neutral non-ionic monomer canbe copolymerized with a monomer that is effective to provide pendantacid groups. Alternatively, acid groups can be added to a non-ionicpolymer through post-reaction modifications.

Monomers that can provide acid groups include an acid anhydride basedmonomer, an ethylenically unsaturated sulfonic acid, an ethylenicallyunsaturated phosphoric acid, an ethylenically unsaturated carboxylicacid, a monoester of an ethylenically unsaturated dicarboxylic acid, ora combination comprising at least one of the foregoing. Specificexamples of the monomers that can provide acid groups include maleicacid anhydride, vinyl sulfonic acid, vinyl phosphoric acid, acrylicacid, methacrylic acid, ethacrylic acid, itaconic acid, maleic acid,fumaric acid, methyl hydrogen maleate, methyl hydrogen fumarate, andethyl hydrogen fumarate. The acid groups can be non-neutralized,partially, or completely neutralized with a metal ion such as sodiumions, potassium ions, zinc ions, magnesium ions, calcium ions, oraluminum ions. lonomers can be derived from one or more monomers thatcan provide acid groups. Neutral non-ionic monomers can optionally beused together with acid group-containing monomers to make the ionomers.Neutral non-ionic monomers include olefins such as ethylene, propylene,butylene, butadiene, and styrene; vinyl acetate; and (meth) acrylates.

Ionic groups can also be grafted to a polymer backbone. For example,maleation is a type of grafting wherein maleic anhydride, acrylic acidderivatives or combinations thereof are grafted onto the backbone chainof a graftable polymer. In an embodiment, the graftable polymer is apolyolefin selected from polypropylene, polyethylene, or a combinationthereof.

A large number of ionomers could be used in the cementing composition,including but are not limited to: carboxylated polyolefins, sulfonatedfluorinated polyolefins, sulfonated ethylene-propylene-diene (EPDM),sulfonated polystyrene, phosphonated polyolefins, and the like.Exemplary carboxylated polyolefins include ethylene acrylic acidcopolymer, an ethylene methacrylic acid copolymer, and anethylene-acrylic acid-methacrylic acid ternary copolymer. Ethylenemethacrylic acid copolymers (E/MAA) are commercially available as SURLYNfrom DuPont or LOTEK from ExxonMobil. Exemplary sulfonated fluorinatedpolyolefins include sulfonated tetrafluoroethylene basedfluoropolymer-copolymer such as NAFION from DuPont (CAS Number66796-30-3).

Without wising to be bound by theory, it is believed that ionic groupscan microphase separate from the non-polar part of polymer chain to formionic clusters, which can act as physical crosslinks. In addition, ionicgroups can also link to the metal cations in the cementitious materialor hydrated cementitious material to produce chemical crosslinks.Exemplary metal cations include calcium ions, aluminum ions, zinc ions,magnesium ions, barium ions, or a combination comprising at least one ofthe foregoing. In the case of bivalent metal cations, a bridge-likecrosslinks can be formed linking two ionomers together or linking anionomer with other components in the component. FIG. 1 illustrates thecrosslinking of two ionomers in the component. As shown in FIG. 1,polymer chains 10 can be crosslinked via the interaction between theionic groups R on the ionomer and the metal cation present in thecomponent. The incorporation of the polymer chains into a component thuscan improve the ductility of the component.

Functionalized filler can also be used to improve the ductility and/ortoughness of the components. Functionalized filler refers to a fillerfunctionalized with one or more functional groups. Exemplary fillersinclude a carbon material, clays, silica, halloysites,polysilsequioxanes, boron nitride, alumina, zirconia, or titaniumdioxide. A carbon material includes a fullerene, carbon nanotube,graphite, graphene, carbon fiber, carbon black, and nanodiamondscombinations of different filler materials can be used. Thefunctionalized clay, functionalized halloysites, functionalizedsilicate, and functionalized silica can be functionalized nanoclay,functionalized nanohalloysites, functionalized nanosilicate, orfunctionalized nanosilica. In an exemplary embodiment, thefunctionalized filler includes functionalized carbon nanotubes. Carbonnanotubes are tubular fullerene structures having open or closed endsand which may be inorganic or made entirely or partially of carbon, andmay include also components such as metals or metalloids. Nanotubes,including carbon nanotubes, may be single walled nanotubes (SWNTs) ormulti-walled nanotubes (MWNTs).

Functional groups include a sulfonate group, a phosphonate group, acarboxylate group, a carboxyl group, a sulfonic acid group, or aphosphonic acid group, or a combination comprising at least one of theforegoing functional groups.

As used herein, “functionalized fillers” include both non-covalentlyfunctionalized fillers and covalently functionalized fillers.Non-covalent functionalization is based on van der Walls forces,hydrogen bonding, ionic interactions, dipole-dipole interactions,hydrophobic or π-π interactions. Covalent functionalization means thatthe functional groups are covalently bonded to the filler, eitherdirectly or via an organic moiety.

Any known methods to functionalize the fillers can be used. For example,surfactants, ionic liquids, or organometallic compounds having thefunctional groups comprising a sulfonate group, a phosphonate group, acarboxylate group, a carboxyl group, a sulfonic acid group, or aphosphonic acid group, or a combination comprising at least one of theforegoing can be used to non-covalently functionalize the fillers.

In an embodiment, boron nitride is non-covalently functionalized with anorganometallic compound having a hydrophilic moiety and a functionalgroup comprising a sulfonate group, a phosphonate group, a carboxylategroup, a carboxyl group, a sulfonic acid group, or a phosphonic acidgroup, or a combination comprising at least one of the foregoingfunctional groups. Exemplary hydrophilic moieties include —CH₂CH₂—O—,—CH₂—CH(OH)—O—, and —OH.

The organometallic compound used to covalently functionalize boronnitride is a compound of the formulas (I), (II), (III), or (IV)

In formulas (I)-(IV), R is a hydrophilic group such as a groupcontaining an ether group, a hydroxyl group, or a combination comprisingat least one of the foregoing. An exemplary R is—CH₂—CH₂—(—O—CH₂—CH₂—O)_(k)—OH, wherein k is zero to about 30. R′ is amoiety containing a sulfonate group, a phosphonate group, a carboxylategroup, a carboxyl group, a sulfonic acid group, or a phosphonic acidgroup, or a combination comprising at least one of the foregoing. R′ hasa structure of formula (V)-(X):

wherein each n is independently 1 to 30, 1 to 20, or 1 to 10; and each Mis independently H or a metal ion such as sodium ions, potassium ions,magnesium ions, barium ions, cesium ions, lithium ions, zinc ions,calcium ions, or aluminum ions.

Various chemical reactions can be used to covalently functionalize thefillers. Exemplary reactions include, but are not limited to,oxidization, reduction, amination, free radical additions, CHinsertions, cycloadditions, polymerization via a carbon-carbon doublebond, or a combination comprising at least one of the foregoing. In someembodiments, the fillers are covalently functionalized. Covalentlyfunctionalized carbon is specifically mentioned. As a specific example,the functionalized filler comprises carbon nanotubes functionalized witha sulfonate group, a carboxylic acid group, or a combination thereof.

In formula (I), x+y=4, x, y are greater than zero. In formulas (II) and(III), x is 1 to 3. In formula (IV), x is 1 or 2.

The filler can be in the particle form or fiber form. In an embodiment,the filler comprises nanoparticles. Nanoparticles are generallyparticles having an average particle size, in at least one dimension, ofless than one micrometer. Particle size, including average, maximum, andminimum particle sizes, may be determined by an appropriate method ofsizing particles such as, for example, static or dynamic lightscattering (SLS or DLS) using a laser light source. Nanoparticles mayinclude both particles having an average particle size of 250 nm orless, and particles having an average particle size of greater than 250nm to less than 1 micrometer (sometimes referred in the art as“sub-micron sized” particles). In an embodiment, a nanoparticle may havean average particle size of about 1 to about 500 nanometers (nm),specifically 2 to 250 nm, more specifically about 5 to about 150 nm,more specifically about 10 to about 125 nm, and still more specificallyabout 15 to about 75 nm.

In an embodiment, the functionalized carbon includes fluorinated,sulfonated, phosphonated, or carboxylated carbon nanotubes. Thesefunctionalized carbon nanotubes could covalently link to the metalcations of in the cementitious material or in the hydrated cementitiousmaterial in a similar way as ionomers do. Exemplary metal cationsinclude calcium ions, aluminum ions, zinc ions, magnesium ions, bariumions, or a combination comprising at least one of the foregoing. FIG. 2illustrates the crosslinking of two functionalized carbon nanotubes inthe cementing composition. As shown in FIG. 2, carbon nanotubes 20 arecrosslinked via the interaction between the ionic groups R on the carbonnanotubes and the metal cation present in the component.

In an embodiment, the ductility modifying agent comprises both thefunctionalized filler and the ionomer. In a specific embodiment, theductility modifying agent comprises both the functionalized carbonnanotubes and ionomers. The component can comprise crosslinks betweenionomers, crosslinks between functionalized fillers, crosslinks betweenionomers and functionalized fillers, or a combination comprising atleast one of the foregoing. In an embodiment, the ionomer, thefunctionalized filler, or both the ionomer and the functionalized fillerare crosslinked with a metal ion in the component. Exemplary metal ionsinclude the ions of magnesium, calcium, strontium, barium, radium, zinc,cadmium, aluminum, gallium, indium, thallium, titanium, zirconium, or acombination comprising at least one of the foregoing. Preferably themetal ions include the ions of one or more of the following metals:magnesium, calcium, barium, zinc, aluminum, titanium, or zirconium. Themetal ions can be part of the cementitious material or the hydratedcementitious material or other components such as fly ash particles aswell as by incorporation salts of cations capable of crosslinkingionomers with ionomers, crosslinking functionalized fillers withfunctionalized fillers, or crosslinking ionomers with functionalizedfillers, or a combination thereof.

FIG. 3 illustrates the crosslinking of the ionomers and functionalizedcarbon in a component. As shown in FIG. 3, a polymer chain 10 can becrosslinked with another polymer chain 10 or crosslinked with afunctionalized filler 20. Similarly, functionalized filler 20 can becrosslinked with another functionalized filler 20 or a polymer chain 10.Without wishing to be bound by theory, it is believed the cementingcomposition can have both improved ductility and improved strength whenthe composition contains both an ionomer and functionalized filler.

Functionalized filler, when present in the components, can be stabilizedwith a stabilizing agent comprising a surfactant, surface-activeparticles, or a combination comprising at least one of the foregoing.The stabilizing agent stabilizes the functionalized filler, inparticular functionalized carbon in an aqueous carrier as a stabilizeddispersion, which can be used to prepare the components. The stabilizingagent can be present in an amount of about 0.1 to 10 wt. % or 0.1 to 5wt. % based on the weight of the components.

Exemplary surfactants include sodium dodecylbenzenesulfonate (SDBS);sodium dodecyl sulfate (SDS); poly(amidoamine) dendrimers (PAMAMdendrimers); polyvinylpyrrolidone (PVP), naphthalenesulfonic acid,polymer with formaldehyde, sodium salt, and cetyl(triethyl)ammoniumbromide (CTAB).

Surface-active particles include Janus particles and non-Janusnanoparticles. The example of Janus particles that can be used tostabilize filler in an aqueous carrier is the Janus graphene oxide (GO)nanosheets with their single surface functionalized by alkylamine. Thefunctionalization method is described in details in Carbon, Volume 93,November 2015, Pages 473-483. Non-Janus nanoparticles that may stabilizefiller in aqueous solution are hydrous zirconia nanoparticles. Withoutwishing to be bound by any theory, it is believed that highly chargedzirconia nanoparticles segregate to regions near negligibly chargedlarger filler particles such as carbon particles because of theirrepulsive Coulombic interactions in solution and stabilize them in theaqueous dispersion.

The metallic fiber comprises steel fiber or iron fiber. The polymericfiber comprises one or more of the following: polyvinyl alcohol fiber;polyethylene fiber; polypropylene fiber; polyethylene glycol fiber; orpoly(ethylene glycol)-poly(ester-carbonate) fiber. Polyvinyl alcoholfibers are specifically mentioned. The fibers can have a length of about0.5 mm to about 20 mm or about 0.5 mm to about 3 mm, and a diameter ofabout 20 microns to about 200 microns or about 30 microns to about 60microns.

The ductility modifying agent can be present in the components in anamount of about 0.1 to about 20 wt. %, based on the total weight of thecomponents, preferably about 1 to about 10 wt. %, based on the totalweight of the components. In an embodiment, the components compriseabout 0.1 to about 8 or about 0.5 to about 3 wt. % of a metal fiber,based on the total weight of the components. When the ductilitymodifying agent comprises the polymer fiber, the ductility modifyingagent can be present in an amount of about 0.1 to about 10 wt. % orabout 0.5 to about 5 wt. %, based on the total weight of the components.In an embodiment, the components comprise about 0.1 to about 10 wt. % orabout 0.5 to about 5 wt. % of an ionomer, based on the total weight ofthe components. In an embodiment, the components comprise about 0.1 toabout 10 wt. % or about 1 to about 5 wt. % of functionalized carbon,based on the total weight of the components. In yet another embodiment,the components comprise about 0.1 to about 10 wt. % or about 1 to about5 wt. % of a functionalized carbon and about 0.1 to about 5 wt. % of theionomer, each based on the total weight of the components.

The component further comprises a cementitious material. Thecementitious material can be any material that sets and hardens byreaction with water. Suitable cementitious materials, including mortarsand concretes, can be those typically employed in a wellboreenvironment, for example those comprising calcium, magnesium, barium,aluminum, silicon, oxygen, and/or sulfur. Such cementitious materialsinclude, but are not limited to, Portland cements, pozzolan cements,gypsum cements, high alumina content cements, silica cements, and highalkalinity cements, or combinations of these. Portland cements areparticularly useful. In some embodiments, the Portland cements that aresuited for use are classified as Class A, B, C, G, and H cementsaccording to American Petroleum Institute, API Specification forMaterials and Testing for Well Cements, and ASTM Portland cementsclassified as Type I, II, III, IV, and V.

The cementitious material can be present in the components in an amountof about 5 wt. % to about 60 wt. % based on the total weight of thecomponents, preferably about 15 to about 50 wt. % of the weight of thecomponents, more preferably about 20 to about 50 wt. %, based on thetotal weight of the components.

The component can contain aggregate. The term “aggregate” is usedbroadly to refer to a number of different types of both coarse and fineparticulate material, including, but are not limited to, sand, gravel,slag, recycled concrete, silica, glass spheres, limestone, feldspar, andcrushed stone such as chert, quartzite, and granite. The fine aggregatesare materials that almost entirely pass through a Number 4 sieve (ASTM C125 and ASTM C 33). The coarse aggregate are materials that arepredominantly retained on a Number 4 sieve (ASTM C 125 and ASTM C 33).In an embodiment, the aggregate comprises sand such as sand grains. Thesand grains can have a size from about 1 μm to about 2000 μm,specifically about 10 μm to about 1000 μm, and more specifically about10 μm to about 500 μm. As used herein, the size of a sand grain refersthe largest dimension of the grain. Aggregate can be present in anamount of about 10% to about 95% by weight of the component, about 10%to about 85% by weight of the component, about 10% to about 70% byweight of the cementing composition, about 20% to about 80% by weight ofthe cementing composition, about 20% to about 70% by weight of thecomponent, 20% to about 60% by weight of the component, about 20% toabout 40% by weight of the component, 40% to about 90% by weight of thecomponent, 50% to about 90% by weight of the component, 50% to about 80%by weight of the component, or 50% to about 70% by weight of thecomponent.

The components further comprise an aqueous carrier fluid. The aqueouscarrier fluid is present in the components in an amount of about 0.1% toabout 30% by weight, specifically in an amount of about 0.5% to about25% by weight, more specifically about 0.5 to about 20 wt. %, each basedon the total weight of the components. The aqueous carrier fluid can befresh water, brine (including seawater), an aqueous base, or acombination comprising at least one of the foregoing. It will beappreciated that other polar liquids such as alcohols and glycols, aloneor together with water, can be used in the carrier fluid. In anembodiment, the components comprise water in an amount of about 0.1% toabout 30% by weight, specifically in an amount of about 0.5% to about25% by weight, more specifically about 0.5% to about 20% by weight, eachbased on the total weight of the components.

The components can further comprise various additives. Exemplaryadditives include a high range water reducer or a superplasticizer; areinforcing agent, a self-healing additive, a fluid loss control agent,a weighting agent to increase density, an extender to lower density, afoaming agent to reduce density, a dispersant to reduce viscosity, athixotropic agent, a bridging agent or lost circulation material, a claystabilizer, or a combination comprising at least one of the foregoing.These additive components are selected to avoid imparting unfavorablecharacteristics to the components, and to avoid damaging the wellbore orsubterranean formation. Each additive can be present in amounts knowngenerally to those of skill in the art.

Weighting agents are high-specific gravity and finely divided solidmaterials used to increase density, for example silica flour, fly ash,calcium carbonate, barite, hematite, ilemite, siderite, wollastonite,hydroxyapatite, fluorapatite, chlorapatite and the like. In someembodiments, about 20 wt. % to about 50 wt. % of wollastonite is presentin the components, based on the total weight of the components. Hollownano- and microspheres of ceramic materials such as alumina, zirconia,titanium dioxide, boron nitride, and carbon nitride can also be used asdensity reducers.

High range water reducers or superplasticizers can be grouped under fourmajor types, namely, sulfonated naphthalene formaldehyde condensed,sulfonated melamine formaldehyde condensed, modified lignosulfonates,and other types such as polyacrylates, polystyrene sulfonates.

Reinforcing agents include fibers such as metal fibers and carbonfibers, silica flour, and fumed silica. The reinforcing agents act tostrengthen the set material formed from the cementing compositions.

Self-healing additives include swellable elastomers, encapsulated cementparticles, and a combination comprising at least one of the foregoing.Self-healing additives are known and have been described, for example,in U.S. Pat. No. 7,036,586 and U.S. Pat. No. 8,592,353.

Exemplary components are provided. In an embodiment, the componentscomprise about 15 wt. % to about 50 wt. % of a cementitious materialsuch as Portland cement, about 20 wt. % to about 60 wt. % of anaggregate such as sand; about 0.5 to about 12 wt. % of an ionomer, morespecifically about 1 wt. % to about 5 wt. % of an ionomer, and about 0.5wt. % to about 12 wt. % functionalized filler, more specifically about 2wt. % to about 8 wt. % of functionalized filler such as functionalizedcarbon nanotubes, each based on the total weight of the components. Thecomponents can also contain about 0.5 wt. % to about 25 wt. % or about0.5 wt. % to about 20 wt. % of water, based on the total weight of thecomponents. Additional additives as disclosed herein can also beincluded in the components.

In another embodiment, the components comprise about 15 wt. % to about50 wt. % of a cementitious material such as Portland cement, about 20wt. % to about 60 wt. % of an aggregate such as sand; and about 0.1 toabout 8 wt. % or about 0.5 wt. % to about 3 wt. % of metallic fiberssuch as steel fibers, each based on the total weight of the components.The components can also contain about 0.5 wt. % to about 25 wt. % orabout 0.5 wt. % to about 20 wt. % of water, based on the total weight ofthe components. Additional additives as disclosed herein can also beincluded in the components.

In still another embodiment, the components comprise about 15 wt. % toabout 50 wt. % of a cementitious material such as Portland cement, about20 wt. % to about 60 wt. % of an aggregate such as sand; and about 1 wt.% to about 10 wt. % or about 1 wt. % to about 5 wt. % of polymericfibers, each based on the total weight of the components. The componentscan also contain about 0.5 wt. % to about 25 wt. % or about 0.5 wt. % toabout 20 wt. % of water, based on the total weight of the components.Additional additives as disclosed herein can also be included in thecomponents.

As a specific example, the components comprise about 25 wt. % to about30 wt. % of a cementitious material such as Portland cement, about 35wt. % to about 45 wt. % of aggregate such as sand; about 5 wt. % toabout 15 wt. % of silica fume; about 5 wt. % to about 10 wt. % of groundquartz, about 0.5 wt. % to about 3 wt. % of a high range water reducer;about 0.5 wt. % to about 3 wt. % of an accelerator; and about 2 wt. % toabout 10 wt. % of metal fibers such as steel fibers, each based on thetotal weight of the components.

As another specific example, the components comprise about 25 to about40 wt. % of a cementitious material such as Portland cement, about 5 wt.% to about 12 wt. % of silica fume, about 5 wt. % to about 15 wt. % ofquartz powder, about 30 wt. % to about 45 wt. % of sand, 0.5 wt. % toabout 7 wt. % of metal fibers, and about 0.1 wt. % to about 5 wt. % of asuperplasticizer, each based on the total weight of the components.

By decreasing the size of the cement components, such as sand, cement,and filler particles size, and fiber diameters, greater synergy ofproperties can be achieved due to increased interfacial area betweencomponents, leading to improved ductility and higher strength. In someembodiments, all the solid particles in the components have a particlesize of less than about 100 microns or less than about 20 microns. Thediameters of the fibers are less than about 100 microns or less thanabout 20 microns.

The ingredients of the components can be mixed together in the presenceof a carrier and then molded or casted forming the component. Thecarrier can be an aqueous carrier fluid and is used in an amount ofabout 1% to about 60% by weight, more specifically in an amount of about1% to about 40% by weight, based on the total weight of the compositionsto form the components.

If necessary, the molded or casted component can be further heat treatedat a temperature of 150° F. to about 1,000° F. and a pressure of about100 psi to about 10,000 psi for about 30 minutes to about one week.Without wishing to be bound by theory, it is believed that the heattreatment can strength the components at a microscopic level.

The components have a compressive strength of about 5 ksi to about 150ksi, specifically about 20 ksi to about 60 ksi. The components can be afrustoconical member or a bottom sub for a downhole tool. In anotherembodiment, combinations of the components are used together for thedownhole tool to control fluid flow.

Exemplary components include casing; liner; casing shoe; mandrels ofpackers, plugs, sandscreens; and centralizers.

An embodiment of a downhole tool that controls fluid flow is show inFIG. 4. Referring to FIG. 4, a downhole 100 includes a frustoconicalmember 101 (also referred to as a cone). A bottom sub 104 is disposed atan end of the tool. A seal member 102 is radially expandable in responseto being moved longitudinally against the frustoconical member. One wayof moving the seal member 102 relative to the frustoconical member 101is to compress longitudinally the complete assembly with a setting tool.(not shown) The tool 100 can also include a slip segment 103 and anabutment member 105 intermediate of the seal member 102 and the slipsegment 103. The frustoconical member 101, the seal member 102, the slipsegment 103, the abutment member 105, and the bottom sub 104 can all bedisposed about an annular body (not shown), which is a tubing, mandrel,or the like.

The frustoconical member 101 includes a first end and a second end,wherein the first end is configured for engagement with the seal member102. Optionally the downhole tool also includes a second slip segment(not shown), which is configured for contact with the frustoconicalmember 101. In an embodiment, the second slip is moved into engagementor compression with the second end of the frustoconical member 101during setting.

The seal member 102 is configured (e.g., shaped) to accept thefrustoconical member 101 to provide force on the seal member 102 inorder to deform the seal member 102 to form a seal with mating surfaces.Illustratively a compressive force is applied to the seal member 102 bya frustoconical member 101 and a setting tool disposed at opposing endsof the seal member (not shown). To achieve the sealing properties, theseal member has a percent elongation of about 10% to about 500%,specifically about 15% to about 200%, and more specifically about 15% toabout 50%, based on the original size of the seal member.

The abutment member 105 prevents the extrusion of the seal member. In anembodiment, the abutment member is a backup ring.

The slip segment 103 comprises a slip body; an outer surface comprisinggripping elements; and an inner surface configured for receiving anannular body. In an embodiment, the slip segment can be made of castiron. The slip segment is configured to be radically altered to engage astructure to be isolated. In an embodiment, the slip segment has atleast one surface that is radially alterable in response to longitudinalmovement of the frustoconical member relative to the slip segment. Theat least one surface being engageable with a wall of a structurepositioned radially thereof to maintain position of at least the slipsegment thus the downhole tool relative to the structure when engagedtherewith.

In an embodiment, the bottom sub 104 is the terminus of a downhole tool(e.g., tool 100). In another embodiment, the bottom sub 104 is disposedat an end of a string. In certain embodiment, the bottom sub 104 is usedto attach tools to a string. Alternatively, the bottom sub 104 can beused between tools or strings and can be part of a joint or coupling. Ina non-limiting embodiment, a first end of the bottom sub 104 provides aninterface with, e.g., the slip segment 103, and a second end of thebottom sub 104 engages a setting tool.

The downhole tool is configured to set (i.e., anchor) and seal to astructure such as a liner, casing, or closed or open hole in an earthformation borehole, for example, as is employable in hydrocarbonrecovery and carbon dioxide sequestration applications.

During setting, tool 100 is configured such that longitudinal movementof the frustoconical member 101 relative to the seal member 102 causesthe seal 102 to expand radially into sealing engagement with astructure. In addition, a pressure applied to the tool urges the sealmember 102 toward the slip segment 103 to thereby increase both sealingengagement of the seal member 102 with the structure to be separated andthe frustoconical member 101 as well as increasing the anchoringengagement of the slip segment 104 with the structure.

Set forth below are various embodiments of the disclosure.

Embodiment 1

A component for a downhole tool comprising: a cementitious material; anaggregate; and a ductility modifying agent comprising one or more of thefollowing: an ionomer; a functionalized filler; the functionalizedfiller comprising one or more of the following: functionalized carbon;functionalized clay; functionalized silica; functionalized alumina;functionalized zirconia; functionalized titanium dioxide; functionalizedsilsesquioxane; functionalized halloysite; or functionalized boronnitride; a metallic fiber; or a polymeric fiber.

Embodiment 2

The component of Embodiment 1, wherein the component is a frustoconicalmember, a bottom sub, or a combination thereof.

Embodiment 3

A downhole tool for controlling the flow of a fluid in a wellbore, thedownhole tool including a component that comprises: a cementitiousmaterial; an aggregate; and a ductility modifying agent comprising oneor more of the following: an ionomer; a functionalized filler; thefunctionalized filler comprising one or more of the following:functionalized carbon; functionalized clay; functionalized silica;functionalized alumina; functionalized zirconia; functionalized titaniumdioxide; functionalized silsesquioxane; functionalized halloysite; orfunctionalized boron nitride; a metallic fiber; or a polymeric fiber.

Embodiment 4

The downhole tool of Embodiment 3, wherein the ionomer, thefunctionalized filler, or both the ionomer and the functionalized fillerare crosslinked with a metal ion in the component.

Embodiment 5

The downhole tool of Embodiment 4, wherein the metal ion comprises oneor more of the following: magnesium ions; calcium ions; strontium ions;barium ions; radium ions; zinc ions; cadmium ions; aluminum ions;gallium ions; indium ions; thallium ions; titanium ions; or zirconiumions.

Embodiment 6

The component or downhole tool of any one of Embodiments 1 to 3, whereinthe metallic fiber comprises steel fiber or iron fiber.

Embodiment 7

The component or downhole tool of any one of Embodiments 1 to 3, whereinthe polymeric fiber comprises one or more of the following: polyvinylalcohol fiber; polyethylene fiber; polypropylene fiber; polyethyleneglycol fibers; or poly(ethylene glycol)-poly(ester-carbonate) fibers.

Embodiment 8

The component or downhole tool of any one of Embodiments 1 to 7, whereinthe ionomer comprises a polymer backbone formed from one or more of thefollowing monomers: an acid anhydride based monomer; an ethylenicallyunsaturated sulfonic acid; an ethylenically unsaturated phosphoric acid;an ethylenically unsaturated carboxylic acid; a monoester of anethylenically unsaturated dicarboxylic acid; ethylene; propylene;butylene; butadiene; styrene; vinyl acetate; or (meth)acrylate; andwherein the ionomer comprises one or more of the following functionalgroups: a sulfonate group, a phosphonate group, a carboxylate group, acarboxyl group, a sulfonic acid group, or a phosphonic acid group.

Embodiment 9

The component or downhole tool of any one of Embodiments 1 to 4, whereinthe ductility modifying agent comprises both the functionalized fillerand the ionomer.

Embodiment 10

The component or downhole tool of any one of Embodiments 1 to 9, whereinthe functionalized filler has one or more of the following functionalgroups: a sulfonate group, a phosphonate group, a carboxylate group, acarboxyl group, a sulfonic acid group, or a phosphonic acid group.

Embodiment 11

The component or downhole tool of any one of Embodiments 1 to 10,wherein the cementitious material comprises one or more of thefollowing: Portland cement; pozzolan cement; gypsum cement; high aluminacontent cement; silica cement; or high alkalinity cement.

Embodiment 12

The component or downhole tool of any one of Embodiments 1 to 11,wherein the component further comprises one or more of the following:wollastonite; silica flour; fly ash; calcium carbonate; barite;hematite; ilemite; siderite; hydroxyapatite; fluorapatite; orchlorapatite.

Embodiment 13

The component or downhole tool of any one of Embodiments 1 to 12,wherein the component comprises about 0.1 wt. % to about 10 wt. % of theductility modifying agent based on the total weight of the component.

Embodiment 14

The component or downhole tool of any one of Embodiments 1 to 13,wherein the component comprises: about 0.5 to about 12 wt. % of thefunctionalized filler; about 0.5 to about 12 wt. % of the ionomer; about15 to about 50 wt. % of the cementitious material; and about 20 to about60 wt. % of the aggregate, each based on the total weight of thecomponent.

Embodiment 15

The component or downhole tool of any one of Embodiments 1 to 13,wherein the component comprises: about 0.1 to about 8 wt. % of themetallic fiber; about 15 to about 50 wt. % of the cementitious material;and about 20 to about 60 wt. % of the aggregate, each based on the totalweight of the component.

Embodiment 16

The component or downhole tool of any one of Embodiments 1 to 13,wherein the component comprises: about 1 to about 10 wt. % of thepolymeric fiber; about 15 to about 50 wt. % of the cementitiousmaterial; and about 20 to about 60 wt. % of the aggregate, each based onthe total weight of the component.

Embodiment 17

The downhole tool of any one of Embodiments 3 to 16, further comprisinga seal member adjacent the component.

Embodiment 18

The downhole tool of any one of Embodiments 3 to 17, wherein thedownhole tool is a frac plug or a bridge plug.

Embodiment 19

A downhole tool for controlling the flow of a fluid in a wellbore, thetool comprising: an annular body having a flow passage therethrough; afrustoconical member disposed about the annular body; a seal membercarried on the annular body and configured to engage a portion of thefrustoconical member; and a bottom sub disposed about the annular body;wherein at least one of the frustoconical member and the bottom subcomprise: a cementitious material; an aggregate; and a ductilitymodifying agent comprising one or more of the following: an ionomer; afunctionalized filler; the functionalized filler comprising one or moreof the following: functionalized carbon; functionalized clay;functionalized silica; functionalized alumina; functionalized zirconia;functionalized titanium dioxide; functionalized silsesquioxane;functionalized halloysite; or functionalized boron nitride; a metallicfiber; or a polymeric fiber.

Embodiment 20

The downhole tool of Embodiment 19, further comprises a slip segmentdisposed about the annular body intermediate of the seal member and thebottom sub.

Embodiment 21

The downhole tool of Embodiment 19 or Embodiment 20, further comprisinga abutment member adjacent the seal member.

Embodiment 22

The downhole tool of any one of Embodiments 19 to 21, wherein at leastone of the frustoconical member and the bottom sub comprise, based onthe total weight of the frustoconical member or the bottom sub: about0.5 to about 12 wt. % of the functionalized filler; about 0.5 to about12 wt. % of the ionomer; about 15 to about 50 wt. % of the cementitiousmaterial; and about 20 to about 60 wt. % of the aggregate.

Embodiment 23

The downhole tool of any one of Embodiments 19 to 21, wherein the atleast one of the frustoconical member and the bottom sub comprise, basedon the total weight of the frustoconical member or the bottom sub: about0.1 to about 8 wt. % of the metallic fiber; about 15 to about 50 wt. %of the cementitious material; and about 20 to about 60 wt. % of theaggregate.

Embodiment 24

The downhole tool of any one of Embodiments 19 to 21, wherein at leastone of the frustoconical member and the bottom sub comprise, based onthe total weight of the frustoconical member or the bottom sub: about 1to about 10 wt. % of the polymeric fiber; about 15 to about 50 wt. % ofthe cementitious material; and about 20 to about 60 wt. % of theaggregate.

All ranges disclosed herein are inclusive of the endpoints, and theendpoints are independently combinable with each other. As used herein,“combination” is inclusive of blends, mixtures, alloys, reactionproducts, and the like. All references are incorporated herein byreference.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. “Or” means “and/or.” The modifier “about” used in connectionwith a quantity is inclusive of the stated value and has the meaningdictated by the context (e.g., it includes the degree of errorassociated with measurement of the particular quantity).

What is claimed is:
 1. A downhole tool for controlling the flow of afluid in a wellbore, the downhole tool including a component, thecomponent comprising: about 15 wt. % to about 50 wt. % of a cementitiousmaterial; about 20 wt. % to about 60 wt. % of an aggregate comprisingsand, gravel, silica, slag, recycled concrete, glass spheres, limestone,feldspar, crushed stone, or a combination comprising at least one of theforegoing; and about 0.1 wt. % to about 10 wt. % of a ductilitymodifying agent, based on the total weight of the component; wherein theductility modifying agent comprises a metal fiber and an ionomer; theionomer comprises a polymer backbone formed from an ethylenicallyunsaturated carboxylic acid; and the component is a molded componentmade from a composition comprising the cementitious material, theaggregate; and the ductility modifying agent.
 2. The downhole tool ofclaim 1, wherein the metal fiber comprises steel fiber or iron fiber. 3.The downhole tool of claim 1, wherein the cementitious materialcomprises one or more of the following: Portland cement; pozzolancement; gypsum cement; high alumina content cement; silica cement; orhigh alkalinity cement.
 4. The downhole tool of claim 1, wherein thecomponent further comprises one or more of the following: wollastonite;silica flour; silica fume; fly ash; calcium carbonate; barite; hematite;ilemite; siderite; hydroxyapatite; fluorapatite; or chlorapatite.
 5. Thedownhole tool of claim 1, wherein the component comprises: about 0.1 toabout 8 wt. % of the metal fiber; about 15 to about 50 wt. % of thecementitious material; and about 20 to about 60 wt % of the aggregate,each based on the total weight of the component.
 6. The downhole tool ofclaim 1, wherein the downhole tool is a frac plug or a bridge plug. 7.The downhole tool of claim 1, wherein the component comprises about 25to about 40 wt. % of a cementitious material, about 5 wt. % to about 12wt. % of silica fume, about 5 wt. % to about 15 wt. % of quartz powder,about 30 wt. % to about 45 wt. % of sand, about 0.5 wt. % to about 7 wt.% of a metal fiber, and about 0.1 wt. % to about 5 wt. % of asuperplasticizer, each based on the total weight of the component. 8.The downhole tool of claim 1, wherein the component is a frustoconicalmember; and the downhole tool further comprises: an annular body havinga flow passage therethrough; a seal member carried on the annular bodyand configured to engage a portion of the frustoconical member; and abottom sub disposed about the annular body, and wherein thefrustoconical member is disposed about the annular body.
 9. The downholetool of claim 1, wherein the component is a bottom sub; and the downholetool further comprises: an annular body having a flow passagetherethrough; a frustoconical member disposed about the annular body; aseal member carried on the annular body and configured to engage aportion of the frustoconical member; and the bottom sub is disposedabout the annular body.
 10. The downhole tool of claim 1, wherein thecomponent further comprises an aqueous carrier in an amount of about 0.1to about 30 wt % based on total weight of the component.
 11. Thedownhole tool of claim 1, wherein all solid particles in the componenthave a particle size of less than about 100 microns.
 12. The downholetool of claim 1, wherein the component has a compressive strength ofabout 5 ksi to about 150 ksi.
 13. The downhole tool of claim 1, whereinthe component has a compressive strength of about 20 ksi to about 60ksi.
 14. The downhole tool of claim 1, wherein the component is afrustoconical member.